Helma B. Wennemers (born 24 June 1969 in Offenbach am Main) is a German organic chemist. She is a professor of organic chemistry at the Swiss Federal Institute of Technology in Zurich (ETH Zurich).
Helma B. Wennemers (born 24 June 1969 in Offenbach am Main) is a German organic chemist. She is a professor of organic chemistry at the Swiss Federal Institute of Technology in Zurich (ETH Zurich).
Helma Wennemers studied chemistry at the Goethe University Frankfurt, completing her diploma thesis with Gerhard Quinkert in 1993. She earned her PhD at Columbia University, New York in 1996, under the supervision of W. Clark Still, with a thesis "Encoded combinatorial chemistry: a tool for the study of selective intermolecular interactions." Between 1996 and 1998, she was a postdoctoral fellow at Nagoya University with Hisashi Yamamoto, before being appointed Bachem Assistant Professor at the University of Basel in 1999. She held this post until 2003, where she was promoted to associate professor. In 2011, she moved to ETH Zurich as a professor of organic chemistry.
Wennemers' research focuses on proline-rich peptides.
Wennemers led the development of tripeptides containing H-Pro-Pro-Xaa type sequences (Pro: proline, Xaa: any amine) as organocatalysts for C–C bond formations based on an enamine mechanism. [1] High reactivity, stereo- and chemoselectivity for aldol [2] or conjugate addition reactions [3] [4] can be achieved by varying the absolute configuration of the single amino acids as well as the functional group of the Xaa residue. The modularity of the peptides enabled creation of catalysts capable of catalyzing the conjugate addition reactions of aldehydes to nitroolefins with as little as 0.05 mol% of tripeptidic catalyst. [5]
She also worked on other organocatalyzed transformations. Inspired by natural polyketide synthases—which use malonic acid half thioesters (MAHTs) as thioester enolate equivalents — she developed organocatalytic methods for stereoselective addition reactions of MAHTs (and protected variants monothiomalonates, MTMs) to electrophiles using cinchona alkaloid derived catalysts. The introduction of fluorinated MAHTs and MTMs allowed for the stereoselective introduction of fluorine substituents in fluoroacetate aldol reactions [6] as well as further addition reactions to imines [7] and nitroolefins. [8]
In chemical biology, Wennemers uses larger proline-rich peptides, such as collagen model peptides or oligoprolines, for applications such as tumor targeting, [9] cell penetration [10] or drug delivery. She utilized Cγ-functionalized proline derivatives for the functionalization and stabilization of short-chained collagen triple helices. Further, she introduced aminoproline [11] and γ-azaproline [12] as pH-sensitive probes to tune the conformational stability of the collagen triple helix by pH change. In the field of cell penetrating peptides (CPPs), Wennemers showed that preorganization of cationic charges along an oligoproline backbone enhanced the cellular uptake of CPPs compared to more flexible oligoarginines with undefined charge display. [10] Moreover, the oligoproline-based CPPs demonstrated a defined nuclear localization and high proteolytic stability as well as low cytotoxicity.
Wennemers utilizes peptides to control the morphology of nanostructured materials for generation of ordered mesoscopic materials. She developed tripeptides for the size-controlled generation of mono-disperse, water-soluble silver-, palladium-, platinum-, and gold nanoparticles. [13] Recently, she reported peptide‐stabilized platinum nanoparticles that have greater toxicity against hepatic cancer cells (HepG2) than against other cancer cells and non‐cancerous liver cells. [14] Wennemers also explored conjugates of oligoprolines and π-conjugated systems that form hierarchical self-assemblies with diverse morphologies (e.g. nanofibers, nanorods, nanosheets). She used such a conjugate to prepare the first example of an extended triaxial supramolecular weave held together through the interplay of weak non-covalent interactions. [15]
Wennemers work was recognized by the Leonidas Zervas Award of the European Peptide Society (2010), [16] the Pedler Award of the Royal Society of Chemistry (2016), [17] the Inhoffen Medal (2017), [18] the Netherlands Scholar Award for Supramolecular Chemistry (2019) [19] and the Arthur C. Cope Scholar Award (2020). [20]
The aldol reaction is a reaction in organic chemistry that combines two carbonyl compounds to form a new β-hydroxy carbonyl compound. Its simplest form might involve the nucleophilic addition of an enolized ketone to another:
In organic chemistry, the Michael reaction or Michael 1,4 addition is a reaction between a Michael donor and a Michael acceptor to produce a Michael adduct by creating a carbon-carbon bond at the acceptor's β-carbon. It belongs to the larger class of conjugate additions and is widely used for the mild formation of carbon-carbon bonds.
In organic chemistry, organocatalysis is a form of catalysis in which the rate of a chemical reaction is increased by an organic catalyst. This "organocatalyst" consists of carbon, hydrogen, sulfur and other nonmetal elements found in organic compounds. Because of their similarity in composition and description, they are often mistaken as a misnomer for enzymes due to their comparable effects on reaction rates and forms of catalysis involved.
The Hajos–Parrish–Eder–Sauer–Wiechert and Barbas-List reactions in organic chemistry are a family of proline-catalysed asymmetric aldol reactions.
Alexander C. Filippou has been a Professor of Inorganic Chemistry at the Rheinische-Friedrich-Wilhelms-University Bonn since 2005.
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Corinna S. Schindler is a Professor of Chemistry at the University of Michigan. She develops catalytic reactions with environmentally benign metals such as iron, towards the synthesis of biologically active small molecules. For her research in the development of new catalysts, Schindler has been honored with several early-career researcher awards including the David and Lucile Packard Foundation Fellowship in 2016, the Alfred P. Sloan Fellowship in 2017, and being named a member of the C&EN Talented 12 in 2017. Schindler has served on the Editorial Board of Organic and Bimolecular Chemistry since 2018.
Vy Maria Dong is a Vietnamese-American Chancellor's Professor of Chemistry at the University of California, Irvine (UCI). Dong works on enantioselective catalysis and natural product synthesis. She received the Royal Society of Chemistry's Merck, Sharp & Dohme Award in 2020, the American Chemical Society's Elias James Corey Award in 2019, and the UCI's Distinguished Alumni Award in 2018.
Richard Dronskowski is a German chemist and physicist. He is a full professor at the RWTH Aachen University.
An Artificial Metalloenzyme (ArM) is a designer metalloprotein, not found in nature, which can catalyze desired chemical reactions. Despite fitting into classical enzyme categories, ArMs also have potential in new-to-nature chemical reactivity like catalysing Suzuki coupling, Metathesis etc., which were never reported among natural enzymatic reactions.
Paul Knochel is a French chemist and a member of the French Academy of Sciences.
Dhevalapally B. RamacharyFTAS, FRSC, FASc, FNASc, also known as D. B. Ramachary, is an Indian chemist and professor at the School of Chemistry, University of Hyderabad. He has made numerous contributions in various fields of chemical science.
Katrina (Kate) Anne Jolliffe is an Australian supramolecular and organic chemist and professor at the University of Sydney.
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Benjamin List is a German chemist who is one of the directors of the Max Planck Institute for Coal Research and professor of organic chemistry at the University of Cologne. He co-developed organocatalysis, a method of accelerating chemical reactions and making them more efficient. He shared the 2021 Nobel Prize in Chemistry with David MacMillan "for the development of asymmetric organocatalysis".
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Alison Wendlandt is an American chemist who is an assistant professor at the Massachusetts Institute of Technology. Her research considers the development of catalysts for organic synthesis.
René Peters is a German chemist and since 2008 Professor of Organic Chemistry at the University of Stuttgart.
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